Rotary kiln



A. B. CARSTENS.

ROTARY KILN.

APPLICATION FILED DEC-8,1919.

Patented May-16, 192

3 SHEET SHEET l.

0 z m O M W 0 2 m o z. w m 6 s o M W o a w ,Ra o & o w v 1 Rf Z A. B.CARSTENS.

ROTARY KILN- APPLICATION FILED DEC-8, I919.

Patented May 16, 19 22.

3 SHEETS-SHEET 2.

awua 14 oz A. B. CARSTENS.

ROTARY KILN.

APPLICATION FILED DEC.8. 1919.

Patented May 16, 1922.

3 SHEETS-SHEET 3.

22% add SVLUQVI OL UNITED STATES PATENT OFFICE.

ALEXANDER B: GABSTENS, F MONTEREY, MEXICO, ASSIG-NOR TO THE ft'MIlimIGANMETAL COMPANY, LIMITED,

A CORPORATION OF NEW YORK.

Romany KILN.

Patented May t, i922,

Application filed December 8, 1919. Serial No. 343,438.

- To all whom it may concern:

' STENS, a citizen of the United States, residing at Monterey, Mexico,have invented certam new and useful Improvements in Rotary Kiln; and Ido hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same.

This invention relates to rotary kilns, roasters, driers, and the like,and particularly to a feeding mechanism for'delivering material to thekiln. Among the uses of the invention may be mentioned burning cementand lime, drying rock, fuels and minerals, agglomerating and nodulizingores, treating iron blast furnace fine dust etc. It is to be understoodthat the foregoing statement is not intended to limit the invention tothe uses specified, it being the aplicants intention to claim all usesto which his invention isadapted.

The present practice in feeding material to be treated to rotary kilnsinvolves theintroduction of' the material at one end of the kiln throughsuitable feeding devices. These feeding devices are in the direct pathof hot gases and dust issuing from the kiln and are subject, therefore,to destructive action which materially shortens their life. Furthermore,in feeding material at the end of the kiln, the material accumulates-andfalls from the kiln instead of passing therethrough as is intended. Thisrepresents a substantial loss, since the material must be collected andrehandled. Much of the material is, moreover, carried from the kiln inthe form of dust and must also be collected and rehandled. J

It is the object of the present invention to provide feeding mechanismfor rotary kilns which is disposed outside the path of the gases in thekiln, and is, therefore, unaffected thereby, and which permits thefeeding of material to tions throughout the length, thereof.

A further object of the invention is the provision of feeding mechanismwhich in sures the deposit of material within the kiln in a mannerpreventing the escape thereof from the end and reducing the amount ofdust to a minimum, thereby increasing the cleanly operation.

the kiln at any section or see Further objects and advantages of theinventlon will be apparent as it is better un derstood by reference tothe following specification, when read in connection with theaccompanying drawing illustrating the preferred embodiments of theinvention, in which,

Fig. l is a transverse section through a 1:0 tary kiln illustrating thefeeding mechanism;

Fig. 2 is an enlarged detail in section of the feeding mechanism;

Fig. 3 is an elevation of a portion of the kiln showing the feedingmechanism;

Fig. 4 is a transverse section illustrating the application of aslightly different form of my invention;

Fi 5 is an enlarged detail in section of the feeding mechanismillustrated in Fig. 4; and

Fig. 6 is an elevation of a portion of a kiln illustrating theapplication of the feedin mechanism shown in Fig. 4.

ly invention comprehends broadly the provision of feeding mechanism. forkilns embodying openings in the kiln spaced longitudinally from the endsof the kiln and provided with closures which normally prevent ingress oregress of material, while nevertheless permitting delivery of materialto the kiln under predetermined conditions. In connection with theopenings, I provide scoops adapted to pick up material from a suitablecontainer or bin, and controlling means for the closures which permitautomatic delivery of the material taken. up by I the scoops to thekiln.

Referring to Figs. 1 to 3 of the drawing, 5' indicates the body of acylindrical kiln which may be rotated in any suit-able mannor from a,source of power, the kiln being supported, for this purpose on rollerbear ings (not shown), in the well known manner. At a point spaced fromthe end of the kiln, a framework 6 is provided tosupport a bin 7 inwhich a Suppl. of material to'be treated, or of fuel, such, f r example,as pulverizedcoal, is maintained, the material being supplied, forexample, from time to time or continuously through a chute 8.

At points spaced about the circumference of the kiln, openings 9 areprovided in the wall thereof, which openings are surrounded by flanges10. pair of closures or doors 11 are supported on shafts 12 mounted forin the arc.

oscillation in the flanges 10. The closures 11 are normally held in theposition indicated in Fig. 2, by springs 13 connecting arms,

14, which are secured to the-shafts 12. One shaft of each pair isprovided with an arm 15, which is connected by a link 16 to an arm 17 ofa bell crank lever 18, secured to the complementary shaft 12, and thebell crank lever l8'is provided with a roller 19.

The frame 6 supports an are 20, braced by struts 21, above the cylinder5. A shoe 22 is secured to the arc 20 by bolts 23 and the shoe may beadjusted circumferentially of the are by removing the bolts 23 andreinserting them in suitable openings provided A cam 24 is pivotallysupp-orted at 25 on the shoe 22 and is provided with a face 26 withwhich the roller 19 contacts as the cylinder 5 rotates,

cillation of the bell crank lever 18 to swing the doors 11 to theposition indicated in Fig. 1. A bolt 27 is pivoted at 28 to the cam 24and is engaged in a suitable opening provided therefor in the arc 20. Aspring 29 surrounds the bolt 27 between the are 20 and the cam 24, andis of such dimensions that it is normally not compressed when the roller19 contacts with the cam face to swing the doors 11. However, if anyobstruction prevents the swinging of the doors l1,'the spring 29 will becompressed to permit the roller to pass the cam, thus providing a safetydevice to prevent breaking of the parts under unusual conditions.

The flanges 10 areextended as indicated in the drawing to provide scoops3O prefedges 31 of hardened steelf These scoopsproject from the kiln 5,and as b the latter erably having rotates, material in the bin 7 ispicked up thereby. When the scoop thus filled with material reaches theuppermost limitof its travel, or the point at which the cam 24 has beenadjusted, the doors 11 are actuated as hereinbefore described to permitthe material to pass into the interior of the kiln. As soon as theroller 19 has passed the cam face 26, the doors thus opened are returnedto their normal position by the gases or dust from spring 13 and escapeof the kiln through the corresponding opening 9 is thereby prevented.

Referring to Figs. 4 to 6 inclusive of the drawing, 35 indicates a kilnsupported and rotated as previously described and provided, in thisinstance, with a refractory lining 36. At a point spaced from the end ofthe kiln, a frame 37 supports a receptacle or bin 38 to which materialis fed continuously or intermittently througha chute 39. The kiln 35 isprovided with spaced openings 40 through which flanges 41 project I andclosures 42 are secured to oscillatory shafts 43 which arepreferablymounted in suitable bearing blocks secured to the thus causing0s its normal position.

collar 45 and spiral springs 46 are secured at one end to the collarsand at the other to the kiln 35, the springs tending to hold theclosures 42 in a diagonal position within the flanges 41 as indicated inF ig. 4. Each of the shafts 43 carries, also, an arm 47 having a roller48.

A transverse member 49 of the frame 37 is provided with a depending arm50 upon which a lever 51' is pivoted at 52. The other end of the lever51 is normally held in a stirrup 53, a weight 54 being hung upon the endof the lever to retain it in the position indicated in Fig. 5. A cam 55is secured to the lever 51 in the path of the rollers 48. Each of theflanges 41 supports a scoop 56, preferably provided with a hardened edge57. As the kiln 35 rotates, the scoops 56 pick up material from the bin38, andas the respective rollers 48 engage the cam 55, the closures 42are oscillated against the tension of the springs 46 to the positionindicated in Fig. 5, permitting the material to drop from the scoop intothe kiln. As soon as a 1 oller 48 passes the cam 55, the spring 46returns the closure 42 to The weight 54 is sufficient to normally holdthe cam 55 in its operative position, but in the event that opening of aclosure is prevented, the weight will be lifted to permit the roller topass, thus I preventing breakage of the mechanism.

From the foregoing, it will be ,apparent that I have perfected anapparatus for feeding material to rotary kilns and the like, which,while extremely simple in construction, provides material advantages. Ithas een demonstrated that by feeding material to the kiln in the mannerdescribed, less dust is formed and none of the material is lost from theend of the kiln, as is common inrotary kilns of the type now employed.Owing to the prevention of the losses noted, the operation is made morecleanlyand the capacity of a kiln of given dimensions is materiallyincreased. It is frequently, moreover, a distinct advantage tofeedmaterial to a kiln at a point spaced from the end thereof, advantagebeing thereby taken of temperature and other conditions whichsubstantially effect the results accomplished in carrying out operationsin the kiln.

Various changes may be made in the form, arrangement and construction ofthe parts, without departing from the invention which I desire to claimbroadly as the the escape of gases therefrom, and means cooperating withsaid first-named means to cause a momentary opening of the'same andthereby permit material to pass through said openings into the kiln.

.2. A rotary kiln having openings intermediate the ends thereof,closures normally preventing escape of gases through said openings,mechanical means for automatically opening said closures as the kilnrotates and means for delivering material through said openings.

3. A rotary kiln having a plurality of openings spaced about itsperipher closures normally preventing escape o gases through saidopenings, mechanical means for automatically opening said closures andmeans projecting from the kiln to receive a supply of material to bedelivered through said openings 4. A rotary kiln having an openingtherein, a closure normally preventing escape of gases through saidopening, mechanical means for automatically opening said closure, ascoop projecting from the kiln at and communicating with said openingand a receptacle from which saidscoop receives material as said kilnrotates.

5. A rotary kiln having an opening intermediate the ends thereof, aclosure normally preventing escape of gases through said opening, ascoop projecting from the kiln at and communicating with said opening, abin from which said scoop receives material, and mechanical means foropening said closure, said means being effective when said scoop hasmoved to a position which permits the material to drop by gravitythrough said opening.

6. A rotary kiln having an opening intermediate the ends thereof, aclosure normally preventing escape of gases through said opening, ascoop projecting from said kiln at and commumcatin with said opening, abin from which sai scoop receives material, actuating means for saidclosure, effective when said scoop has moved to a position which permitsthe material to drop by gravity through said opening, and means wherebythe actuating means is ineffective when said closure is prevented fromopening.

7. A'rotary kiln having an opening intermediate its ends, a bin beneathsaid kiln,

means on said kiln, surrounding said o-pening, to receive and elevatematerlal from said bin, a closure normally preventing escape of gasesfrom said opening, mechanical means for opening said closure at apredetermined point in the rotation of said kiln, and means whereby theactuating means is ineffective when said closure is prevented fromopening.

9. A rotary kiln having an opening therein, a bin beneath the kiln, ascoop surrounding said opening and projecting from the kiln, a closurenormally preventing escape of gases from said opening, resilient meansbiasing said closure to closed position and cam actuated means foropening said closure.

10. 'A rotary kiln having a plurality of therein spaced about theperiphery openin thereo a bin beneath'the kiln, a scoop surrounding eachopening and projecting from the kiln, a closure for each openingresiliently biased to closedposition and means for successively openingsaid closures as said kiln rotates to permit material picked up by saidscoops to pass into the kiln.

In testimony whereof I afiix my signature.

ALEXANDER B. GARSTENS.

